Process for manufacturing metal caps for electric incandescent lamps



Feb, 2 192$.

L. P. GRANER PROCESS FOR MANUFACTURING QETAL CAPS FOR ELECTRIC INCANDESCENT LAMPS Filed NOV. 17, 1923 NP 1 MP S u I d a L by v His 'Attown ey.

Patented Fish 2, 1926.

FEE

LADISLAUfi PETER QRANER, OF EIN'DI-IDVEN, NETHERLANDS, AfiSIG-NOR, BY MESNE ASSlGIiTMElTTS- '16 GENERAL ELECTRIC COMPANY, A; CORPORATION OF YORK.

PRUCESS F833 MANUFAC'IYURING METAL CABS FOR ELIZICTBIC INCANDEEtCTENT LAMP$.

Application filed November 17, 1923. Serial No. M55100.

lie it known that LADISLAUS-PETER (luiixi'zu, u suhieet oi? the Hungarian State, insulin; at lliiidhoven. in the Province of North Bruhzint, in the Kingdom of the li ethei'lm'ulsi have invented certain new and useful luipi'oveniients in or Relating to Processes for i\lm'ui'tuetuiing Metal Cups for lllei-ti'ie Ineandeseent limi'ips of which the ill following is u specification.

i This invention relates to an iinpmved metal can tor: electric lumps end the like, such for multiple as eleetiie glowlein glow-ilist'lmige luinlt-s, vapour lumps, t

When using: inelul mg; for electric luuniis end the like the dmwhuel: exnei'ieueeil that the eup extends heyontl the lninpholdei' so that, it. is possible to touch parts of the 39 cup under tension.

in order to obviate this: disadvantage it has already heeu n'onosed to provide the luinp-holdeir in sueh 3 way with an ii'isuluting' ring 01 eneveltrpo that the latter wholly protects the protruding putt, of the can under tension. Also cups of insulating: nun teiiul. lune 'uli'eiuly been inn nu iuetuied .iieeoidiug to the intention lRIl1D-l10ltlGlfS of no 'innl (Ollflil'iitfilt'lll unity he used The part of the metal enp adjacent the lump howevezyis surrounded by u inetul vino",

whit-h. is insulated with regard to the trap.

It will he evident that the motel ring til ways i-einuii deed. nnd home mounted on the port ut the can that extends beyond the luinn-l'iolclei' when the eat}? is fS't'ltlYMl in the risk oi teuehiug ['Jftil'S under tension is'oliuiiniited Ol Zli least eonsidei'uhly reduced. Aeeoiwlingr to. the invention the. ting l ixed to the cup 'pi'oieruhly hy insulating nmtei'iul that u; the same (line HOFWS its; a eenienh en insulntiiur lllillOl'lzll the z-iuhstunee under the registered trade nun-l; helcelite O1 hulielir'ied paper may he used. it may he ensily applied in u thin layer and utter? hurdeniug it, is perfectly ndupted to rigidly unite the ring and the cap, ltn n 'l ion hulielite shows the advantage that, onee hardened it does not nielt at the temierntui'e necessary for cementing the cap to the, lz'imp Whilst. its insulating capacity does not decrease ut'u, higher tenn'uu utiu e.

Bakelite is an artificial resin that is every- 57 where on the market and it is produced by eondensat-ion of formaldehyde and phenols. it exists in three forms which are called A B and C and which by heat are transformed in each other, when starting with bakelite A, At ordinary temperatures lmkelite is in. a liquid state. or in a solid state, yellow or eoloui'less and soluble in alcohol, acetone, phenol, etc. It is fusible when it is in. e solid state Bakelite i3 is an intermediate product hnltelite C is the final orodnct of (iii the condensation, it is infusible and insoluble in. ztll. even alkaline solvents. Where in this specification reference is made to the hardening of hulzelite the transformation oi hnlcelite i l-into l)1l(0lil"3 G is meant.

By way of exzunple the accompanying (hinting l'Cl'lIQSLlllIS a cap according; to one eniluulinient ot the invention.

The "up l, which is provided With the metal ring 3 is cemented in the known manner to the electric lump The cap land the metal ring 3 tire -separated from each other by the layer G oi? insulating nietei'iul.

in the. drawing the lamp-holder 4; of non nnil eonti-uetion provided with the insulating ring 5 is shown in clotted lines so that it is visible. that it is made impossible to touch any partof the can under tension owing to the use of the metal ring- 3.

'lhe (-211) may be manufactured in a very simple manner. especially if the putt that. is to he iusulutedhy the, ring, is cylindrical.

The process of nianu'tuetin'ing; the im picoyed 21 ps according to the invention is as follows iii) The putt to he insulated is coated with u hiyot' ot the insulating; medium in a liquid Oi in 1, dissolved state, said insulating niediuim after being; dried, serving as u eeinent. such for example as shellac. ilhen the in-- J sulutin medium is dry the metal ring is applied after being suitably heated or the dried insulating niediuin inny first he (noted afresh with a layer of; the insulating medium in :1 liquid 03 in :1 dissolved state, so to make the ring udhei'e to the insulating medium. The ring may he applied to the cup prior or subsequent to cementing the cup to the lump, but pi'etei'nhly this operution. is performed prior to the cementing.

Another process according to the invention whieh is pertioulrirly :ulvnnte'geous is the following:

The nut-t ot the cup that is to he insulated is coated with it layer oi paper that has been immersed in liquid bakelite A or in a solution of bakelite' A. After the layer is .dry, its surface is moistened afresh with liquid. bakelite A or with a solution of bakelite A. Then a metal ring is pushed around the layer which is still moist, the aggregate is dried and the bakelite is transformed by heat into bakelite C The solution of the bakelite may for ex ample be an alcohol solution and the drying may be performed in a vacuum.

The transformation of the bakelite may he preferably performed by gradually raising the temperature. At-about 300? C. bakclite A- is Wholly transformed into bakelite C.

The application of the process according to the invention ensures a rigid attachment of the metal ring to the cap and at the same time good insulation. When having a thickness ofahout mm. the insulating layer may be easily resist a voltage of 500 volts.

The invention may also be applied to advantage. to caps in which a condenser is mounted. As a rule such caps have somewhat larger dimensions than the normal ones so that they further extend beyond the holders and the risk of touching the caps under tension .is greater.-

- What I claim is:

l. The process of applying a protecting ring and insulation above the base of the cap ofan electric lamp or the like which consists in coating the metallic base of the cap'with a liquid'insulating medium and allowing it to dry, and heating the metal ring and placing it over the applied insulation and allowing it to set; i

2. The rocess of applying a protecting ring and insulation about the base of the cap of an electric lamp or the like which consists in coating the metallic base of the on with a liquid insulating medium and al owing it to dry and thereafter applying more of the insulation over the dried insulation and thereat'lcr' placing a metallic ring in a heated condition over the insulating material and allowing it to set.

3. The process of applying a protecting ring and insulation about the base of the cap of an electric lamp or the like which consists in applying a layer of paper over the base of the cap after the paper has been immersed in liquid containing hakolite. allowing the paper to dry in position and. thereafter applying bakelite" solution again to the paper, placing the protecting ring over the paper and insulation while in a heated condition and thereafter heating the aggregate to dry and harden.

In testimony whereof I aiiix my signature.

LADISLAUS P TER GRANER. 

